The invention relates to a rotary kiln and more particularly to an improvement in the front wall refractory support and the rotary kiln adjacent thereto.
The kiln front wall refractory support member, referred to as the smile, has a history of failures which necessitated costly kiln downtime and repairs. In addition the end of the kiln adjacent the feed chute, called the nose ring, allowed partially incinerated waste material to spill over into the air inlet damper requiring frequent removal and reburning of the spilled material.
The front wall refractory support, referred to as the smile because of it appearance from within the kiln, is made of mild steel and has oil passages disposed therein for cooling the structure. It supports refractory that protects the front wall from temperatures between 1500.degree. F. and 220.degree. F. which exist in the kiln due to the introduction of solid charges of waste into the kiln. The front section has been an area requiring continuing repair. The high temperatures cause accelerated corrosion due to oxidation. During the three years the incinerator has been in operation, the smile area has been replaced once and repaired numerous times. The failures were due to cracks in the smile which allowed oil to escape into the kiln. To repair the cracks the kiln had to be shut down and allowed to cool so the cracks could be ground out and seal welded.